Amanda Karoline Rodrigues Nunes

Descrição morfológica e morfométrica da glândula vesicular de cobaias durante o desenvolvimento pós-natal

Vesicular glands are essential for reproduction since their secretions affect sperm function. Guinea pigs (Cavia porcellus) are an excellent experimental model for studying vesicular glands, but no morphologic and morphometric data during its development are available. In the present study, the morphology (projections of the folds (PF) and epithelial tissue high (EH) of the mucosa) and the morphometry (mass (GM), volume (GV), length (GC), width of the portions cranial (CRW), medium (MW) and caudal (CAW)) of the vesicular glands were determined at 1, 3, 5, 8, and 11-weeks of age in male guinea pigs (n = 5/age group). In addition, body mass (BM), body length (BL) and height (BH) and organo-somatic index (OSI) were also determined and the simple correlation coefficient (r) was established between the variables. The glands were restricted to the pelvic cavity, and had its interior filled with a semi-solid mass and, after S8, they occupied also the abdominal cavity and the contents were increased significantly. The mucous membrane presented variable folding and simple columnar epithelium. BM, BL and BH increased continuously with age. GM, GV, GC and CAW did not change from 1 to 5-weeks of age, but increased at 8-weeks of age; GM, GV and LCA also increased at 11-weeks of age. OSI and PF increased at 8 and 11-weeks of age and EH at 5, 8 and 11-weeks of age. There was significant (r) between age, body and glandular parameters; OSI and GM at 8 and 11-weeks of age; age and PF, age and EH and between PF and EH. In conclusion, the guinea pigs vesicular glands followed morphology observed in rats and hamsters, but differed in some aspects from others histricomorfs, can be used as experimental model and its morphological and morphometric development can be divided into three phases: 1 to 5-weeks of age, when they are discrete; 6 to 8-weeks of age when they are generally sharp and >8-weeks of age, when there is an intense increase of the secretory capacity.

Análise morfológica e funcional do processo espermatogênico em cobaios (Cavia porcellus) da pré-puberdade até a pós-puberdade

This study describes the morphological and functional analysis of spermatogenesis in guinea pigs (Cavia porcellus) with five (W5), six (W6), nine (W9) and eleven (W11) weeks of age (n=5/group). The aspects analyzed include counts of cell populations present in stage 1 of seminiferous epithelium cycle (SEC), efficiency of spermatogonial mitosis (EMi), meiotic production (EMe), overall yield of spermatogenesis (EOS), Sertoli cell index (SCI) and carrying capacity of Sertoli cells (CCSC). The results showed that the average number of spermatogonia type A, primary spermatocytes in pre-leptoteno/leptoteno, primary spermatocytes in pachytene, total spermatogenic cells and Sertoli cells showed numerical variations according to age; however they were statistically not detected, while round spermatids increased significantly at puberty and then stabilized. The spermatogenic production of 5 to 11-week-old guinea pigs did not reach the stabilization point, and the RMi, RME, EOS, SCI and CCSC showed significant number variation as a function of age. The results demonstrate that Cavia porcellus in post-pubertal stage 2 are an advantageous experimental model to address studies on the processes of homologous recognition, alignment, and synapsis during meiotic prophase; intrinsic yield of spermatogenesis in guinea pigs is similar to Wistar rats, paca and agouti (Dasyprocta sp.) and lower than in cavies, whereas the functional efficiency of Sertoli cells is higher than in agouti and Wistar rats, and lower than in pacas, spiny rat and collared peccaries. We conclude that in guinea pigs the spermatogenesis is fully established at 6 weeks of age, indicating the pubertal stage of sexual development, and until week 11 they do not reach the maximum daily sperm production and therefore sexual maturity.